I too have had 4 TKR's and massive amounts of scar tissue removed only to return.  I moved to Indianapolis after having my records sent to Dr. Shelbourne's clinic.  Their PT protocol is much gentler and they have a device called an "elite seat" that really has given me relief in straightening my legs (both knees TKR's) Bear in mind that I saw Dr. Shelbourne's clinic (Dr. Urch is my doctor) a year after my last revision and a year of pt in NY.  While I can't say for sure, I believe my knees would not have as much scar tissue if I had this pt protocol from the beginning.  For one thing, the therapy is much gentler and that elite seat has given me relief since it's done a great job of straightening my legs.  I have improved but am still on morphine and limited because a year passed before I had this therapy.  Dr. Urch has said Dr. Shelbourne and he have not seen the scar tissue problems they once did before developing this type of therapy.....except from people like me who had different therapy.  All I can say is my knees were bent 70 degrees when I first went to see them and was in really severe pain.  after several months of their therapy and that great elite seat, my knees are about 90 degrees.  He wants to get me to 95 degrees and has mentioned possibly arthroscopically removing some scar tissue and then doing the therapy immediately.  Of course he's worried it may not work.....I've had a lot of surgery and they don't want to put me through more and not have it work but I get the feeling they feel the fault lies in the type of therapy most of us have.  I know Dr. Shelbourne's protocol is out there for other OS......but wonder why more do not follow this.  I want less pain and long to get off morphine.